The present invention relates to electric fans, and relates more particularly to such an electric fan which can be controlled to produce currents of hot air or currents of cold air alternatively.
U. S. Pat. No. 5,230,606, issued to the present inventor, discloses an electric fan with hot air/cold air dual-mode control which can be controlled to produce a current of cold air for cooling the people or a current of hot air for warming a room. This structure of electric fan is functional. However, it is complicated in structure, and therefore its manufacturing cost is high.